This application was submitted in support of the 2010 Chemistry and Biology of Tetrapyrroles GRC. The meeting, which is limited to 135 participants, is unique in the field of tetrapyrroles, as there is no other meeting with a similar tradition of broad disciplinary participation. The program will focus on recent advances in tetrapyrrole biology and chemistry including the rapidly growing areas of tetrapyrroles in energy generation in plants and solar energy cells, the emerging role of tetrapyrroles in cell signaling, regulation and human disease;tetrapyrrole trafficking in prokaryotic and eukaryotic systems, and novel mechanistic reactions, both biological and synthetic. The meeting will highlight key areas of progress in the field in which the chemistry and biology inform or advance new medical, agricultural or technological developments. This proposal will address two specific aims: 1) To provide a forum for the discussion of cutting edge unpublished research between basic and clinical scientists, who have a common interest in the chemistry and biology of tetrapyrrole molecules. 2) To bring together and promote the exchange of ideas between established and new investigators from a wide variety of scientific disciplines (e.g., chemistry, biophysics, biochemistry, plant and animal biology, microbiology, and biotechnology) with their clinical counterparts;by providing ample discussion time following formal presentations;holding poster sessions that serve as a focus for the discussion of common interests;and, by fostering a collegial atmosphere that promotes translational research ideas and collaborations. Topics of interest to the medical community include inborn errors of heme metabolism and erythroid development, heme degradation and oxidative stress, heme uptake and utilization in bacterial pathogenesis, and the role of tetrapyrroles as imaging and therapeutic molecules. This meeting will explore the frontiers of tetrapyrrole research as it relates to inbornerrors of porphyrin metabolism, gene regulation and disease. In addition important newresearch in the area of synthetic porphyrins as imaging and therapeutic molecules indiseases such as cancer will be presented.